(A) Field of the Invention
The present invention relates to a circuit and method for playing back digital data in a displayer; and, particularly, the present invention is a circuit and method for playing back digital data for reducing the power consumption of computer system, and allowing the displayer itself playing back video data.
(B) Description of Related Art
The current computer systems, including the portable computer, all regard the CD-ROM as a standard peripheral for data reading device and/or digital video data playing back device. The typical computer system requests the central processor unit (CPU) being completely connected to read the playing back CD-ROM or the video data in the hard drive. For the current computer architecture, the playing back of video data in the computer still can control the peripheral equipment to play back through the operation system inside the computer and the common power supply. In other words, if the user wants to play back the video data through the CPU or CD-ROM, he has to turn on the whole computer, and maintains a certain power supply to the motherboard and other peripheral equipment. At this time, the motherboard and other peripheral equipment, such as hard drive, keyboard and displayer, etc., will naturally consume a certain level of power. Moreover, the current newer types of computers provide the so-called sustaining mode, for example the power-saving mode entered by the computer not used for another period of time. But, this type of sustaining mode can make the CD-ROM and other components in the computer being power off simultaneously, and also make the peripheral equipment of the computer system having the function of playing back video data alone.
Thus, in the conventional computer system, when the user conducts the operation of playing back video data, he still has to turn on the whole computer, and then execute the operation system (OS) through starting the Basic Input/Output System (BIOS), and play back the video data through the CPU or CD-ROM. Nevertheless, the starting of the peripheral equipment will cause unnecessary power consumption. Especially for the portable computer, the situation of power consumption will be more obvious.